An analog mixer incorporating a digital effector has been conventionally known (for example, see NPL1). The analog mixer has plural analog input channels (ch), and each analog input channel has plural analog circuit blocks such as a compressor circuit, an equalizer circuit, a fader circuit, and an output circuit. Each of analog signals inputted to each analog input channel is controlled in dynamic amplitude property by the compressor circuit, controlled in frequency property by the equalizer circuit, adjusted in static amplitude property by the fader circuit and the output circuit, and supplied to a stereo bus, a MIX bus, and an effector bus.
The stereo bus and the MIX bus each mix supplied analog signals and output the mixed analog signal to a corresponding analog output channel.
An analog signal mixed in the effector bus is converted into a digital signal by an AD converter and is inputted to a DSP (Digital Signal Processor). The DSP performs processing to add a system effect to the digital signal. The system effect refers not to an effect added to an individual signal of each channel, but to an effect added to a signal mixed on the effector bus, that is, an effect as the entire mixer. The digital signal to which the system effect is added is converted into an analog signal in a DA converter and is inputted to an effector input channel. In the effector input channel, the static amplitude property of the inputted analog signal is adjusted by the analog fader circuit, the output circuit and the like, and an analog signal after being adjusted is supplied to the stereo bus and the MIX bus.
Further, among analog mixers, there is one in which an external effector can be inserted in an input channel. This mixer is such that the external effector is inserted at a joint position between blocks of plural analog circuit blocks, an effect is added by an external effector to a signal taken out from this position, and the result is returned again to this position.
On the other hand, as a semiconductor integrated circuit used as an audio signal processing device, for example, there is known one such that a CPU, a DSP, an internal RAM, a waveform I/O, and control I/O and so on are mounted in one chip, such as that described in, for example, PTL1.